Computing technology has become small enough and useful enough that the general public is now carrying small computing devices on a daily basis. Initially designed to perform a specific function, such as voice communication or storing a personal address book, these devices are increasingly becoming multi-faceted in their capabilities. In addition to providing a platform upon which a wide array of applications can run, these devices are arriving on store shelves with a number of built-in technologies such as short range connectivity, like Bluetooth and IR, and Internet connectivity, like WiFi and General Packet Radio Service (GPRS). Based on these combinations of technology, it is now possible to offer products and services that find and match users based on their location and/or proximity.
Along with these advances comes a broader acceptance of the usage of those technologies for social purposes. There is an increasing number of people who are comfortable with, and accustomed to, using technology for social means, whether using the Internet to find a date, or using their PDAs to beam business cards. This convergence of technology and social interaction creates an opportunity for a new group of location or proximity based applications. These applications are aimed for fostering interactions, enhancing existing relationships, and enabling collaboration.
Ubiquitous computing envisions “smart,” everyday items that sense their surroundings and cooperate with one another. These include cell phones, PDAs, laptops, mice, keyboards, printers, cameras, earpieces for telephones, pens, televisions, and other everyday items, equipped with an Internet connection and a Bluetooth transceiver (or other recognition device). For example, a device equipped with a Bluetooth transceiver creates a short-range communication space radiating in all directions from the device, like a bubble with the device in the center. When individuals with devices equipped with Bluetooth transceivers come within close physical proximity, their respective communication spaces (or bubbles) overlap, enabling their personal mobile devices to discover and identify each other. This can be used to facilitate, augment, and promote face-to-face interactions. Furthermore, the device can be associated with a commercial entity, such as a retail outlet. This enables value-added, personalized consumer-business interactions.
All this provides opportunities for these devices, and the applications on these devices, to change how people interact and cooperate, not only between people but also between people and businesses. They contribute to a richer more valuable social experience and help promote sociability in an increasingly impersonal world. Human beings have an inherent characteristic desire for social interactions. Any encounter with another person offers a chance for conversation, for informal information exchange, for collaboration towards a common goal, and to pursue and further personal goals.
There are many methods and systems for implementing these kinds of location or proximity based applications. For instance, PanGo Proximity Platform™, www.saw-you.net, www.imahima.com, and www.trepia.com use proximity based applications. However, these current technologies have several shortcomings, including privacy issues, scalability issues, interoperability issues, and overall user experience. In fact, the majority of such systems are not truly location-based but rather depend on constant user input to demonstrate value. Furthermore these products and services are focused on specific geographical regions, and are targeted for specific uses (e.g., dating, finding nearby friends).
Several proximity aware systems have been developed. These proximity aware systems are described in R. Borovoy, et al., “Meme Tags and Community Mirrors: Moving from Conferences to Collaboration”, Proceedings of 1998 ACM Conference on Computer Supported Cooperative Work, 1998, ACM Press; Holmquist, et al., “Supporting Group Awareness with Inter-Personal Awareness Devices”, Journal of Personal Technologies, Vol. 3(1-2), p. 1321, Springer Verlag, 1999; G. Kortuem, “Proem, A Middleware Platform for Mobile Peer-to-Peer Computing”, ACM SIGMOBILE Mobile Computing and Communications Review (MC2R), Special Feature on Middleware for Mobile Computing, Vol. 6, No. 4, October 2002; and G. Korteum, et al., “When Peer-to-Peer Comes Face-to-Face: Collaborative Peer-to-Peer Computing in Mobile Ad-hoc Networks”, Proceedings of 2001 International Conference on Peer-to-Peer Computing, August 27-29, 2001, Linkoping, Sweden, 2001. Some of the proximity aware systems utilize a purely peer-to-peer method of information exchange. There are many drawbacks to such systems. For example, peer-to-peer systems require a fairly large specialized application residing on the device. These applications can be resource intensive, consuming relatively large amounts of CPU time, memory, and storage, all of which are relatively scarce on mobile devices. Additionally, peer-to-peer systems are limited to only the discovery of the nearest neighbors of each of the devices. Data synchronization is also unsatisfactory, since neighboring devices are not aware of any changes in data on a nearby device until that data is re-sent. Peer-to-peer systems also have availability drawbacks because such devices must stay within a predetermined range of each other during the time required to establish pair-wise connections and perform data exchange. Finally, peer-to-peer systems sometimes present the problem of disclosing private information that users have not explicitly authorized to be disclosed.
Other proximity aware systems add a storage server. These proximity aware systems are described in P. Dahlber, et al., “Proxy Lady: Mobile Support for Opportunistic Communication”, Scandinavian Journal of Information Systems 13(1), 2001; and J. Bergvist, et al., “Location Awareness and Local Mobility: Exploring Proximity Awareness”, Proceedings of the 22nd IRIS Conference (Information Systems Research Seminar in Scandinavia), University of Jyväiskylä Press, 1999. The storage server is only used for periodic non-real-time data synchronization. This approach alleviates some of the storage requirements on the devices. Additionally proximity aware systems exist that are used specifically for gaming purposes. One such system is described in S. Björk, et al., “Pirates!—Using the Physical World as a Game Board”, Interact 2001, IFIP TC.13 Conference on Human-Computer Interaction, July 9-13, Tokyo, Japan. All of the above mentioned limitations hold, however, because the data exchange between devices in these systems is still peer-to-peer. All of these systems used specialized hardware and communication protocols specially designed for that particular system.
Other proximity aware systems add a registry server. These systems are described in T. Kindberg, et al., “People, Places, Things: Web Presence for the Real World”, Mobile Networks and Applications (MONET), 7(5), October 2002, 365-376 and T. Kindberg, et al., “Implementing physical hyperlinks using ubiquitous identifier resolution”, Proceedings of the Eleventh International World Wide Web Conference, WWW2002, Honolulu, Hi., USA, 7-11 May 2002, ACM, 2002, 191-199. This registry server acts as a static listing of name-value pairs associating arbitrary information with physical objects. This allows objects to be “tagged” with information, however no context-aware matching is performed.
The highly dynamic nature of mobile ad-hoc networks require timely and efficient algorithms through which a computing device can detect the presence of neighboring devices. These algorithms should enable moving devices to discover each other without overloading the network with traffic. Several distributed decentralized discovery algorithms have been proposed (e.g., Theodoros Salonidis, et al., “Distributed Topology Construction of Bluetooth Personal Area Networks”, Proceedings of IEEE INFOCOM 2001, Anchorage, Ak., 2001; Theodoros Salonidis, et al., “Proximity Awareness and Fast Connection Establishment in Bluetooth”, Proceedings of the First Annual ACM Workshop on Mobile Ad Hoc Networking and Compubint (MOBIHOC), Boston, Mass., 2000; Michael Nidd, “Service Discovery in DEAPspace”, IEEE Personal Communications, pp. 39-45, August 2001; Salonidis, et al., U.S. patent application Pub. No. US 2003/0096576 A1, “Method and Apparatus for Connecting Devices Via an Ad Hoc Wireless Communication Network”; and Hermann, et al., U.S. patent application Pub. No. US 2002/0176391 A1, “Method and Device for Prompt and Efficient Service Discovery in Wireless Networks”). The decentralization of these ad-hoc networks for which these algorithms are employed are a drawback that usually results in relatively complex algorithms.